This invention relates to a printing apparatus and a printing method for printing a variety of information such as images and characters on a recording medium, such as a card. More particularly, this invention relates to a printing apparatus and a printing method that are capable of switching printing methods according to characteristics of a recording medium or information for printing a variety of information.
Conventionally, a thermal transfer printing apparatus has been used to record a desired image or a character on a card recording medium such as a credit card, a cash card, a license card or an ID card by thermally transferring with a thermal head via a thermal transfer film. As an example, in Japanese Patent Publication (TOKKAI) No. 09-131930, a printing apparatus using a direct transfer method has been disclosed. The apparatus directly transfers an image and a character to a recording medium via a thermal transfer film. This method has an advantage of attaining a high quality image due to thermal sublimate ink. However, the recording medium needs to have a receptive layer on its printing surface to receive the ink. Therefore, only limited recording medium can be used, or the receptive layer needs to be formed on the surface of the recording medium.
Generally, a card made of a polyvinyl chloride (known as a PVC card) has been widely used as the recording medium that can receive the thermal sublimate ink. However, since the PVC card generates toxic substances when burned, recently it has been tried to switch to a card made of a polyethylene terephthalate (also known as a PET card).
Furthermore, in recent years, a new type of card media such as an IC card, which embeds an IC chip or antenna inside, has been used in a variety of fields. Because of the embedded elements, this type of card has an uneven surface, resulting in a printing problem.
In Japanese Patent Publication (TOKKAI) No. 08-332742, a printing apparatus using an indirect transfer technology, in which an image is transferred to an intermediate transfer medium once then transferred to a final recording medium, has been disclosed to solve the above problem. According to this method, it is possible to overcome the problems such as limited recording medium related to the receptive layer or the issue of printing on an uneven surface of the recording medium. Furthermore, this method makes it easier to print an image on an entire surface of the card medium as opposed to the direct transfer method.
In Japanese Patent Publication (TOKKAI) No. 11-263032, an image forming portion for forming an image on a belt-shaped transfer sheet (an intermediate transfer film) is disposed at an upper portion, and a retransfer portion for re-transferring the image transferred to the transfer sheet to a card as the received image is disposed at lower portion. When the image is formed on the transfer sheet, the sheet is transported in a vertical direction with respect to the apparatus. While the card is being transported in a horizontal direction after passing a sheet return path, the image is re-transferred to the card.
Further, in Japanese Patent Publication No. 08-58125, a thermal transfer printing apparatus that prints simultaneously to both front and back surfaces of a recording paper is disclosed. The apparatus is configured to have two printing mechanisms; namely a mechanism of transferring an ink image to a recording paper surface by a heat roller after forming an image on an intermediate transfer film using a thermal head, and another mechanism of transferring an ink to a backside of the recording paper with another thermal head different from the aforementioned thermal head. The thermal head for transferring the ink to the backside of the recording paper surface through an ink film is arranged at a side opposite to the heat roller for the re-transfer process.
However, in the intermediate transfer method, a running cost tends to be higher than that of the direct transfer method because of the intermediate transfer medium. Also, it takes longer time to finish printing. Furthermore, in terms of a card design, there are many cases where a front side needs to be printed on a whole area while only limited area such as precautions for card use is needed to print on a backside. Thus, there are merits and demerits for both printing methods. In Japanese Patent Publication No. 11-263032, an image forming process and a re-transferring process can be performed simultaneously, but the apparatus can handle only the aforementioned indirect transfer method. Also, in Japanese Patent Publication No. 08-058125, a disclosed technology for simultaneous processing on both sides is limited to the same recording paper. When a process error occurs while processing both sides, it is necessary to re-form an image for not only either side but also a recording sheet on the intermediate transfer film. Furthermore, to properly print on both sides of the same recording paper with the thermal transfer printing apparatus disclosed in the publication, as both sides of the recording paper are heated, it becomes difficult to peel the intermediate transfer film off because of a high temperature.
Therefore, it is possible to reduce a running cost by selecting a method most appropriate to a recording medium if a printing apparatus can switch between the direct transfer method and the indirect transfer method to print an image on a recording medium depending on an objective of printing such as an entire surface printing. Also, and if it is possible to select either of at least the direct transfer method and the indirect transfer method without limitation to the front and back sides of the same recording medium and printing simultaneously to a plurality of recording medium, printing times can be shortened, thereby resulting in the expanded use of such a printing apparatus.
An object of the present invention is to provide a printing apparatus that can switch between the direct transfer method and the indirect transfer method for printing and shorten a print processing time.
Another object of the present invention is to provide a printing apparatus that reduces an operating cost associated with printing and simplifies a printing process as well as improves a printing speed while meeting an increasing demand for both the direct transfer method and the indirect transfer method for printing a recording medium.
Still another object of the present invention is to provide a printing method that can switch between the direct transfer method and the indirect transfer method and shorten a print processing time.
Further objects and advantages of the invention will be apparent from the following description of the invention.
To attain the objectives, in the first aspect of the present invention, a printing apparatus is equipped with a recording medium transport device for transporting a recording medium supplied from a supply portion along a transport path; at least one first printing device arranged on the transport path of the recording medium transport device for selectively forming an image on the recording medium via a thermal transfer film with an ink layer and on an intermediate transfer medium for temporarily holding the image; a thermal transfer film transport device for transporting the thermal transfer film; a second printing device arranged on the transport path of the recording medium transport device for transferring the image formed on the intermediate transfer medium on the recording medium or another recording medium; an intermediate transfer medium transport device for reciprocating the intermediate transfer medium with regard to the second printing device; and a control device for controlling the second printing device to execute the image forming at the same time when transporting the thermal transfer film for forming the image by the first printing device.
In this aspect, the recording medium transport device transports the recording medium from the supply portion along the transport path. At least one first printing device is arranged on the transport path of the recording medium transport device, and the first printing device forms an image selectively on a recording medium via a thermal transfer film having an ink layer and on an intermediate transfer medium that temporarily holds the image. When the first printing device forms the image, the thermal transfer film transport device transports the thermal transfer film. Also, the second printing device is arranged on the transport path of the recording medium transport means, and the second printing device transfers the image formed on the intermediate transfer medium to the same recording medium or another recording medium. The intermediate transfer medium transport device moves back and forth the intermediate transfer medium with regard to the second printing device. Also, the control device controls the second printing means so that the image forming is executed in parallel to the transporting of the thermal transfer film when the first printing device forms the image. According to this aspect, the first printing device transfers the image directly to the recording medium, and the second printing device transfers the image indirectly to the recording medium or another recording medium. Thus, it is possible to switch between the direct transfer method and the indirect transfer method to print the recording medium. Also, because the second printing device forms the image while transporting the thermal transfer film for the first printing device to form the image, the second printing device and the first printing device form the image simultaneously, thereby shortening a processing time for printing several recording media.
Further in this aspect, a recording medium turning portion may be arranged on the transport path of the recording medium transport device and between the first printing device and the second printing, device for rotating or inverting the recording medium. The first printing means forms an image on one side of the recording medium and the second printing device forms an image on the other side of the same or another recording medium. In this case, it becomes possible to change a transport direction of the recording medium using the recording media turning portion. Therefore, after the first printing device forms the image on one side of the recording medium, it is possible to form the image on the other side sequentially using the second printing device to enable double-side printing.
In the second aspect of the present invention, an printing apparatus is equipped with a recording medium transport device for transporting a recording medium supplied from a supply portion along a transport path; at least one first printing device arranged on the transport path of the recording medium transport device for selectively forming an image on the recording medium and an intermediate transfer medium for temporarily holding the image; a second printing device arranged on the transport path of the recording medium transport device for transferring the image formed on the intermediate transfer medium on the recording medium or another recording medium; an intermediate transfer medium transport device for reciprocating the intermediate transfer medium with regard to the second printing means; a mode setting device for selecting a mode between the first mode in which the first printing device forms the image on the recording medium and the second mode in which the second printing device transfers the image formed on the intermediate transfer medium by the first printing device to the same or another recording medium; and a control device for controlling the second printing device to form the image at the same time when transporting the intermediate transfer medium back and forth for forming the image on the intermediate transfer medium by the first printing device.
In this aspect, the recording medium transport device transports the recording medium from the supply portion along the transport path. At least one first printing device is arranged on the transport path of the recording medium transport device, and the first printing device selectively forms the image on a recording medium and on an intermediate transfer medium that temporarily holds the image. Also, the second printing device is arranged on the transport path of the recording medium transport device, and the second printing device transfers the image formed on the intermediate transfer medium to the recording medium or another recording medium. The intermediate transfer medium transport means moves the intermediate transfer medium reciprocally with regard to the first and the second printing devices. In the mode setting means, it is selected to use the first mode for forming the image an the recording medium using the first printing device or the second mode for transferring the image formed on the intermediate transfer medium by the first printing means to the same or a different recording medium using the second printing means. The control device controls the second printing device to forms the image in parallel to the back and forth transportation of the intermediate transfer medium when the first printing device forms the image on the intermediate transfer medium. According to this aspect, when the printing apparatus uses the first mode, the first printing device transfers the image directly to the recording medium. When set to use the second mode, the second printing device prints the image indirectly on the recording medium or another recoding medium. Therefore, it is possible to switch between the direct transfer method and the indirect transfer method to print the recording medium. Also, because the second printing device forms the image on the recording medium in the second mode while reciprocally transporting the intermediate transfer medium for the first printing device to form the image, the second printing device and the first printing device form the image simultaneously, thereby shortening a processing time for printing several recording media.
In this embodiment, a parallel drive device may be provided to drive the recording medium transport device to transport the recording medium to the second printing device and the intermediate transfer medium transport device to transport the intermediate transfer medium in parallel. Thus, it is possible to transport the recording medium and the intermediate transfer medium back and forth independently in parallel so the transporting time associated with printing is shortened.
Furthermore, in the third aspect of this invention to attain the aforementioned objectives, a printing method includes the first image forming process and the second image forming process. In the first image forming process, the first recording medium or an intermediate transfer medium for temporarily holding an image is transported to the first image forming position, and an image is formed selectively on the first recording medium or the intermediate transfer medium at the first image forming position. In the second image forming process, the second recording medium is transported to the second image forming position, and the image formed on the intermediate transfer medium is transferred at the second image forming position. At least a part of the first image forming process and a part of the second image forming process are executed simultaneously.
According to this aspect, in the first image forming process, the first recording medium and the intermediate transfer medium are transported to the first image forming position, and the image is selectively formed to the first recording medium or the intermediate transfer medium at the first image forming position. In the second image forming process, the second recording medium is transported to the second image forming position, and the image formed on the intermediate transfer medium is transferred to the second recording medium at the second image forming position. At least a portion of the first image forming process and a portion of the second image forming process are executed simultaneously. According to this aspect, the image is directly transferred to the first recording medium in the first image forming process and indirectly transferred to the second recording medium in the second image forming process. Therefore, while it is possible to switch between the direct transfer method and the indirect transfer method when printing the recording medium, at least a portion of the first image forming process and a portion of the second image forming process are executed simultaneously thereby shortening the print processing time. In such a case, it is acceptable to form the image on the second recording medium in the second image forming process while moving the first recording medium and the intermediate transfer medium back and forth when forming the image on the first recording medium and the intermediate transfer medium.
Other objectives and features of the present invention shall be clearly explained in a detailed description of the preferred embodiment below based upon the drawings provided.